"Better wait a bit," Tom suggested. "There may be powder gas in there. Some of it must have blown forward."
"I don't care!" excitedly cried the professor. "That is the hidden city! I'm sure of it! I have found it at last! I must go in and examine it!"
"There'll be plenty of time," said Tom. "It isn't going to run away. Wait until I make a test Tim, hand me one of those torches."
Some torches of a very inflammable wood were used to test for the presence of the deadly smoke-gas. Lighting one of these, Tom tossed it into the big excavation.
It fell to the stone floor—to the stone street to be more exact—and, flaring up brightly, further revealed the rows of houses as they stood, silent and uninhabited.
"It's all right," Tom announced. "There's no danger so long as the torch burns. You can go on, Professor."
And Professor Bumper rushed forward, scrambling over the pile of blasted rock, followed by Tom and the others. Some of the debris from the explosion had fallen into the cave, and was scattered for some distance along the main street of what had been Pelone. But beyond that the way was clear.
"Yes, it is Pelone," cried Professor Bumper. "See!"
He pointed to inscriptions in queer characters over the doorway of some of the houses, but he alone could read them.
"I have found Pelone!" he kept repeating over and over again.